Hayakawa S, Ohno N, Okada S, Kobayashi M
Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Hiroshima, Japan.
Clin Exp Immunol. 2017 Nov;190(2):268-279. doi: 10.1111/cei.13008. Epub 2017 Aug 10.
Regulatory T cells (T ) control immune responses by suppressing various inflammatory cells. T in newborn babies may play an important role in preventing excessive immune responses during their environmental change. We examined the number and phenotype of T during the neonatal period in 49 newborn babies. T were characterized by flow cytometry using cord blood (CB) and peripheral blood (PB) from the early (7-8 days after birth) and late (2-4 weeks after birth) neonatal periods. CD4 forkhead box protein 3 (FoxP3 ) T cells were classified into resting T (CD45RA FoxP3 ), activated T (CD45RA FoxP3 ) and newly activated T cells (CD45RA FoxP3 ). Compared with CB and PB during the late neonatal period, the percentage of T and all T subpopulations in the CD4 lymphocyte population were increased significantly during the early neonatal period. Furthermore, the proportion and absolute number of activated T were increased markedly compared with other T subpopulations, such as resting T and newly activated T cells (non-T ), in the early neonatal period. Increased T concomitantly expressed the suppressive molecule cytotoxic T lymphocyte antigen-4 (CTLA-4). The up-regulated expression of chemokine receptor 4 (CCR4) and down-regulated expression of CCR7 were also observed in expanded T . When cord blood cells were cultured in vitro with CD3 monoclonal antibodies (mAb) for 5 days, CD4 CD45RA FoxP3 cells were increased significantly during the culture. Thus, the presence of increased activated T in early neonates may play an important role in immunological regulation by suppressing excessive T cell activation caused by the immediate exposure to ubiquitous antigens after birth.
调节性T细胞（T细胞）通过抑制各种炎症细胞来控制免疫反应。新生儿的T细胞可能在其环境变化期间预防过度免疫反应中发挥重要作用。我们检测了49例新生儿在新生儿期T细胞的数量和表型。使用出生早期（出生后7 - 8天）和晚期（出生后2 - 4周）的脐带血（CB）和外周血（PB），通过流式细胞术对T细胞进行表征。CD4叉头框蛋白3（FoxP3）T细胞被分为静息T细胞（CD45RA FoxP3）、活化T细胞（CD45RA FoxP3）和新活化T细胞（CD45RA FoxP3）。与新生儿晚期的CB和PB相比，新生儿早期CD4淋巴细胞群体中T细胞及其所有亚群的百分比显著增加。此外，与其他T细胞亚群，如静息T细胞和新活化T细胞（非调节性T细胞）相比，新生儿早期活化T细胞的比例和绝对数量显著增加。增加的T细胞同时表达抑制性分子细胞毒性T淋巴细胞抗原4（CTLA - 4）。在扩增的T细胞中还观察到趋化因子受体4（CCR4）表达上调和CCR7表达下调。当脐带血细胞在体外与CD3单克隆抗体（mAb）培养5天时，培养期间CD4 CD45RA FoxP3细胞显著增加。因此，早期新生儿中活化T细胞数量增加可能通过抑制出生后立即接触普遍存在的抗原所导致的过度T细胞活化，在免疫调节中发挥重要作用。
